Lakings D B, Friis J M, Bruns M B
Drug Metabolism Research, Upjohn Company, Kalamazoo, MI 49001.
J Chromatogr. 1988 Jun 24;428(1):131-9. doi: 10.1016/s0378-4347(00)83897-9.
A high-performance liquid chromatographic method has been defined for the determination of eclanamine (free base of eclanamine maleate) and two of its metabolites, N-desmethyleclanamine and N,N-didesmethyleclanamine in urine. The method employs 10-ml urine samples, has a linear range from 5 to 500 ng/ml for the three compounds, and has a detection limit of 0.5 ng/ml for each compound. Sample preparation uses a cyanopropylsilane extraction column with washes of water, acetonitrile-water (30:70, v/v), and acetonitrile, and elution with 2% trifluoroacetic acid in acetonitrile. The eluate is evaporated to dryness, the residue dissolved in 1.0 ml acetonitrile-water (10:90, v/v) and 100 microliter are injected onto a Supelcosil LC-CN column. Eclanamine and its metabolites are eluted with an acetonitrile-water (35:65, v/v) eluent containing 0.01 M triethylamine and adjusted to pH 7.0 with phosphoric acid. The method has been validated by preparing and analyzing a series of fortified urines (range 2-500 ng/ml for each compound) on four separate days. Good linearity, precision, reproducibility, and specificity were obtained. Certification of the analytical method was accomplished by analyzing urine specimens collected from one volunteer administered a single oral dose of 45 mg eclanamine maleate. The data suggest that the metabolites of eclanamine have long elimination half-lives with levels still quantifiable in the 72-96 h collection interval.
已确定一种高效液相色谱法，用于测定尿液中依克那明（马来酸依克那明的游离碱）及其两种代谢物N-去甲基依克那明和N,N-二去甲基依克那明。该方法采用10毫升尿液样本，三种化合物的线性范围为5至500纳克/毫升，每种化合物的检测限为0.5纳克/毫升。样品制备使用氰丙基硅烷萃取柱，依次用水、乙腈-水（30:70，v/v）和乙腈冲洗，并用2%三氟乙酸乙腈溶液洗脱。洗脱液蒸发至干，残渣溶于1.0毫升乙腈-水（10:90，v/v）中，取100微升注入Supelcosil LC-CN柱。依克那明及其代谢物用含有0.01 M三乙胺且用磷酸调至pH 7.0的乙腈-水（35:65，v/v）洗脱液洗脱。该方法通过在四个不同日期制备和分析一系列加标尿液（每种化合物范围为2至500纳克/毫升）进行了验证。获得了良好的线性、精密度、重现性和特异性。通过分析从一名口服单剂量45毫克马来酸依克那明的志愿者收集的尿液标本完成了分析方法的认证。数据表明，依克那明的代谢物消除半衰期长，在72 - 96小时收集间隔内水平仍可定量。
